This invention relates to an antiskid apparatus for automotive vehicles.
An example of a conventional antiskid apparatus for automotive vehicles is disclosed in the specification of Japanese Patent Publication (KOKOKU) No. 49-28307.
As shown in FIG. 2, the conventional antiskid apparatus has an inlet solenoid valve 3 arranged between a master cylinder 1 and a wheel brake 2, and an outlet solenoid valve 5 arranged between the wheel brake 2 and a reservoir 4. A pump 6 is arranged between the reservoir 4 and the master cylinder 1 and the circuit arrangement is such that a working fluid discharged from the pump 6 circulates to the master cylinder 1 and inlet solenoid valve 3.
Thus, the circuit arrangement is such that the working fluid is circulated between the master cylinder 1 and inlet solenoid valve 3 in the conventional antiskid apparatus. Consequently, when the inlet solenoid valve 3 is cut off during operation of the antiskid function, the fluid pressure increases between the inlet solenoid valve 3 and pump 6 when there is an increase in pressure at the wheel brake 2. Since the fluid pressure is applied directly to the master cylinder 1, the brake pedal 7 is forced backward. When there is a decrease in pressure at the wheel brake 2, the fluid pressure between the inlet solenoid valve 3 and pump 6 decreases, as a result of which the pedal 7 is drawn inward. Owing to repetition of this phenomenon, a large pedal shock is produced and the driver is subjected to discomfort and unease.